You don't mention if you have a std/tourer or an interstate.
The standard uses a T6.5 12v 3watt.
I did a write up with led's and honda rebel harness here
http://www.valkyrieforum.com/bbs/index.php/topic,35394.0.htmlYou can use the led here without having to change the harness.
http://www.superbrightleds.com/moreinfo/subminiature-bulbs/24-led-bulb-1-smd-led-wedge-base/229/If you have any questions let me know. Ride safe.
Chris